Initial commit

2 files changed, 319 insertions, 0 deletions

diff --git a/cube/cube.go b/cube/cube.go
new file mode 100644
index 0000000..f52cf8f
--- /dev/null
+++ b/cube/cube.go
@@ -0,0 +1,129 @@
+package cube
+
+import (
+	"errors"
+	"strings"
+)
+
+type colour uint8
+
+const (
+	White colour = iota
+	Yellow
+	Red
+	Orange
+	Blue
+	Green
+)
+
+func (c colour) String() string {
+	switch c {
+	case White:
+		return "W"
+	case Yellow:
+		return "Y"
+	case Red:
+		return "R"
+	case Orange:
+		return "O"
+	case Blue:
+		return "B"
+	case Green:
+		return "G"
+	}
+	return ""
+}
+
+type row []colour
+
+func (r row) String() (s string) {
+	for i := range r {
+		s += r[i].String()
+	}
+	return
+}
+
+type face []row
+
+func (f face) colGet(c int) (r row) {
+	r = make(row, len(f))
+	for i := 0; i < len(f); i++ {
+		r[i] = f[i][c]
+	}
+	return
+}
+
+func (f *face) colSet(c int, r row) {
+	for i := 0; i < len(*f); i++ {
+		(*f)[i][c] = r[i]
+	}
+}
+
+type Cube struct {
+	front  face
+	back   face
+	top    face
+	bottom face
+	left   face
+	right  face
+}
+
+func New(size int) (*Cube, error) {
+	if size < 1 {
+		return nil, errors.New("Size must be greater than 0.")
+	}
+	var c Cube
+	c.front = make(face, size)
+	c.back = make(face, size)
+	c.top = make(face, size)
+	c.bottom = make(face, size)
+	c.left = make(face, size)
+	c.right = make(face, size)
+
+	for i := 0; i < size; i++ {
+		c.front[i] = make(row, size)
+		c.back[i] = make(row, size)
+		c.top[i] = make(row, size)
+		c.bottom[i] = make(row, size)
+		c.left[i] = make(row, size)
+		c.right[i] = make(row, size)
+
+		for j := 0; j < size; j++ {
+			c.front[i][j] = Red
+			c.back[i][j] = Orange
+			c.top[i][j] = White
+			c.bottom[i][j] = Yellow
+			c.left[i][j] = Green
+			c.right[i][j] = Blue
+		}
+	}
+
+	return &c, nil
+}
+
+func (c Cube) Size() int {
+	return len(c.front)
+}
+
+func (c Cube) String() (r string) {
+	s := strings.Repeat(" ", c.Size()+2)
+
+	for i := 0; i < c.Size(); i++ {
+		r += s + c.top[i].String() + "\n"
+	}
+	r += "\n"
+
+	for i := 0; i < c.Size(); i++ {
+		r += c.left[i].String() + "  " +
+			c.front[i].String() + "  " +
+			c.right[i].String() + "  " +
+			c.back[i].String() + "\n"
+	}
+	r += "\n"
+
+	for i := 0; i < c.Size(); i++ {
+		r += s + c.bottom[i].String() + "\n"
+	}
+
+	return
+}
diff --git a/cube/turns.go b/cube/turns.go
new file mode 100644
index 0000000..2129f26
--- /dev/null
+++ b/cube/turns.go
@@ -0,0 +1,190 @@
+package cube
+
+func (a *row) flip() {
+	for left, right := 0, len(*a)-1; left < right; left, right = left+1, right-1 {
+		(*a)[left], (*a)[right] = (*a)[right], (*a)[left]
+	}
+}
+
+func (f *face) transpose() {
+	l := len(*f)
+	nf := make(face, l)
+
+	for i := 0; i < l; i++ {
+		nf[i] = make(row, l)
+		for j := 0; j < l; j++ {
+			nf[i][j] = (*f)[j][i]
+		}
+	}
+
+	for i := 0; i < l; i++ {
+		for j := 0; j < l; j++ {
+			(*f)[i][j] = nf[i][j]
+		}
+	}
+}
+
+func (f *face) clockwise() {
+	f.transpose()
+
+	for i := 0; i < len(*f); i++ {
+		(*f)[i].flip()
+	}
+}
+
+func (f *face) _clockwise() {
+	for i := 0; i < len(*f); i++ {
+		(*f)[i].flip()
+	}
+
+	f.transpose()
+}
+
+func (c *Cube) Y(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.top.clockwise()
+	} else if _layer == 0 {
+		c.bottom._clockwise()
+	}
+
+	temp := c.front[layer]
+	c.front[layer] = c.right[layer]
+	c.right[layer] = c.back[layer]
+	c.back[layer] = c.left[layer]
+	c.left[layer] = temp
+}
+
+func (c *Cube) Y_(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.top._clockwise()
+	} else if _layer == 0 {
+		c.bottom.clockwise()
+	}
+
+	temp := c.front[layer]
+	c.front[layer] = c.left[layer]
+	c.left[layer] = c.back[layer]
+	c.back[layer] = c.right[layer]
+	c.right[layer] = temp
+}
+
+func (c *Cube) U() {
+	c.Y(0)
+}
+func (c *Cube) U_() {
+	c.Y_(0)
+}
+
+func (c *Cube) D() {
+	c.Y_(c.Size() - 1)
+}
+func (c *Cube) D_() {
+	c.Y(c.Size() - 1)
+}
+
+func (c *Cube) Z(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.front.clockwise()
+	} else if _layer == 0 {
+		c.back._clockwise()
+	}
+
+	temp := c.top[_layer]
+	c.top[_layer] = c.left.colGet(_layer)
+	c.top[_layer].flip()
+	c.left.colSet(_layer, c.bottom[layer])
+	c.bottom[layer] = c.right.colGet(layer)
+	c.bottom[layer].flip()
+	c.right.colSet(layer, temp)
+}
+
+func (c *Cube) Z_(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.front._clockwise()
+	} else if _layer == 0 {
+		c.back.clockwise()
+	}
+
+	temp := c.top[_layer]
+	c.top[_layer] = c.right.colGet(layer)
+	c.bottom[layer].flip()
+	c.right.colSet(layer, c.bottom[layer])
+	c.bottom[layer] = c.left.colGet(layer)
+	temp.flip()
+	c.left.colSet(_layer, temp)
+}
+
+func (c *Cube) F() {
+	c.Z(0)
+}
+func (c *Cube) F_() {
+	c.Z_(0)
+}
+
+func (c *Cube) B() {
+	c.Z_(c.Size() - 1)
+}
+func (c *Cube) B_() {
+	c.Z(c.Size() - 1)
+}
+
+func (c *Cube) X(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.right.clockwise()
+	} else if _layer == 0 {
+		c.left._clockwise()
+	}
+
+	temp := c.top.colGet(_layer)
+	temp.flip()
+	c.top.colSet(_layer, c.front.colGet(_layer))
+	c.front.colSet(_layer, c.bottom.colGet(_layer))
+	t := c.back.colGet(layer)
+	t.flip()
+	c.bottom.colSet(_layer, t)
+	c.back.colSet(layer, temp)
+}
+
+func (c *Cube) X_(layer int) {
+	_layer := c.Size() - layer - 1
+
+	if layer == 0 {
+		c.right._clockwise()
+	} else if _layer == 0 {
+		c.left.clockwise()
+	}
+
+	temp := c.top.colGet(_layer)
+	t := c.back.colGet(layer)
+	t.flip()
+	c.top.colSet(_layer, t)
+	t = c.bottom.colGet(_layer)
+	t.flip()
+	c.back.colSet(layer, t)
+	c.bottom.colSet(_layer, c.front.colGet(_layer))
+	c.front.colSet(_layer, temp)
+}
+
+func (c *Cube) R() {
+	c.X(0)
+}
+func (c *Cube) R_() {
+	c.X_(0)
+}
+
+func (c *Cube) L() {
+	c.X_(c.Size() - 1)
+}
+func (c *Cube) L_() {
+	c.X(c.Size() - 1)
+}